From 42c14bf930cfae9d54c9846f51b7b6a8d0e47597 Mon Sep 17 00:00:00 2001
From: Stephen Marz <stephen.marz@utk.edu>
Date: Sun, 26 Apr 2020 08:40:43 -0400
Subject: [PATCH] Check and use permission bits in ELF for user pages.

---
 risc_v/src/elf.rs  |  6 +++---
 risc_v/src/test.rs | 14 +++++++++++++-
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/risc_v/src/elf.rs b/risc_v/src/elf.rs
index d0c8712..6f1d164 100755
--- a/risc_v/src/elf.rs
+++ b/risc_v/src/elf.rs
@@ -47,9 +47,9 @@ pub struct ProgramHeader {
 
 pub const TYPE_EXEC: u16 = 2;
 
-pub const PROG_READ: u8 = 4;
-pub const PROG_WRITE: u8 = 2;
-pub const PROG_EXECUTE: u8 = 1;
+pub const PROG_READ: u32 = 4;
+pub const PROG_WRITE: u32 = 2;
+pub const PROG_EXECUTE: u32 = 1;
 
 pub const MACHINE_RISCV: u16 = 0xf3;
 pub const PH_SEG_TYPE_NULL: u32 = 0;
diff --git a/risc_v/src/test.rs b/risc_v/src/test.rs
index db2d9fe..8adb684 100644
--- a/risc_v/src/test.rs
+++ b/risc_v/src/test.rs
@@ -222,6 +222,18 @@ pub fn test_elf() {
 			}
 			memcpy(ptr.add(ph.off), buffer.get().add(ph.off), ph.memsz);
 			let pages = ph.memsz / PAGE_SIZE + 1;
+			let mut bits = EntryBits::User.val();
+			// This sucks, but we check each bit in the flags to see if
+			// we need to add it to the PH permissions.
+			if ph.flags & elf::PROG_EXECUTE != 0 {
+				bits |= EntryBits::Execute.val();
+			}
+			if ph.flags & elf::PROG_READ != 0 {
+				bits |= EntryBits::Read.val();
+			}
+			if ph.flags & elf::PROG_WRITE != 0 {
+				bits |= EntryBits::Write.val();
+			}
 			for i in 0..pages {
 				let vaddr = ph.vaddr + i * PAGE_SIZE;
 				let paddr = ptr as usize + i * PAGE_SIZE;
@@ -229,7 +241,7 @@ pub fn test_elf() {
 					table,
 					vaddr,
 					paddr,
-					EntryBits::UserReadExecute.val(),
+					bits,
 					0,
 				);
 			}